Sidewall sampler



March 5, 1963 F. v. PORTER 3,030,005

' SIDEWALL SAMPLER dri inal Filed Nov. 28, 1952 IN V EN TOR.

United States Patent Oil ice iatented Mar. 5, 1963 3,8803% SIDEWALLSAWLER Forrest V. Porter, Monterey Park, Calii, assignor to DresserIndustries, Inca, Dallas, Tern, a corporation of lrelaware Division ofapplication Ser. No. 791,598, Dec. 6, 1957. Continuation of applicationSer. No. 322,963, Nov. 28, 1952. This application June 6, 195%, Ser. No.740,337

3 Claims. (Ci. 175-2) This invention relates to the determination of thegeological formations traversed by well boreholes, and more especiallyto methods and apparatus for obtaining samples from the side walls ofpreviously drilled earth boreholes at any desired depth.

This application is a division of application Serial No. 701,698, filedDecember 6, 1957, now US. Patent 2,879,- 972, which is, in turn, acontinuation of application Serial No. 322,963, filed November 28, 1952now abandoned.

During the drilling of a well, the drilling operator is vitallyinterested in the type of geological strata through which the wellborehole passes, since an accurate knowledge of the subsurfaceformations is necessary in order to determine when the well borehole hasreached certain formations in which casing may be set or from whichproduction may be expected. In a locality in which a plurality ofboreholes have been drilled, a map of the contour of the formationsunderlying the entire locality may be obtained by correlating theinformation gleaned from samples taken from each well. Cores of largesize are most desirable from a geological standpoint. A variety ofmethods for obtaining core samples in connection with the drillingoperations are widely used, but are subject to certain disadvantages,particularly the mixing with the samples of well or drilling fiuids,over prolonged periods of drilling which affects the accuracy of thesamples obtained. Other widely used methods of core sampling independentor" the main drilling operations pro vide for separate drilling of coresat an angle or laterally into the formations surrounding the borehole,or the obtaining of solid sample portions of the formations by methodsemploying the firing of hollow bullets or hollow core sampling barrelsor tubes into the surrounding fiormations to dislodge or entrap thesamples. In these types of sampling, difficult problems or"satisfactorily collecting the samples and raising them to the top of thewell are encountered.

The foregoing disadvantages of heretofore known methods of core samplingor sidewall sampling are overcome in the present invention, which ispreferably, although not necessarily, accomplished by a conductor cableoperated sampling tool, which is constructed and arranged to cut orbreak away from the borehole wall, tapered, conical or wedge-shapedsamples of the formation, by the use of explosive cutting means of theshaped charge type. The samples thus released from the formation areimmediately collected in a suitable catcher or trailer-like portion ofthe apparatus, which is preferably closed aiter receiving the formationsamples to shield the samples from washing contact with contaminatingwell fluids while the apparatus is withdrawn from the borehole.

It is accordingly an object of the invention to provide a novel sidewall sampler for use in obtaining data relative to the stratasurrounding w ll boreholes.

Another object of the invention is to provide an improved apparatus forcutting out and obtaining samples of the side wall formations of wellboreholes by the use of shaped charge cutting apparatus of novel design.

A funther object of the invention is to provide core sampl ng apparatusas described, employing a novel means for collecting the samplesobtained from the formations surrounding the borehole, at the same timethe samples are out or broken away from the formations.

Another object of the invention is to provide an improved conductorcable operated side wall sampler employing a shaped charge cuttingoperation, and a retrieving apparatus for the samples which isconditioned and actuated by the explosive force or" the shaped chargeduring the cutting of the samples from the well formation.

The foregoing and other objects, advantages and features of novelty ofthe invention will appear to be brought out more fully in the followingspecification, reference being had to the accompanying drawings whereinlike reference characters refer to like parts.

In the drawings:

FIG. 1 is a View in sectional elevation of the apparatus of theinvention; and

FIG. 2 is a view of the apparatus of FIG. 1 after ac tuation.

FIGS. 1 and 2 show a preferred embodiment of the invention comprising ahead member so connected at the top by threads 13 to a cable head 14into which is anchored a supporting conductor cable, not shown. Securedto the lower end portion of the head member 6! by threaded connection61, is a downwardly-extending tubular upper body member 62. A centraltie rod 63 extends coaxially downward from a threaded connection 64 inthe center of the lower end of the head member 6%, to a threadedconnection 7i) in the center of the upper end of a bull plug 66. Anupwardly-extending tubular lower body member 65, is supported by andattached to the upper end of the bull plug 66 by means of screws 71-awhich extend through the lower margin of the body member into an annularlocking groove 71 formed in and adjacent the upper end portion of thebull plug 66. The upper and lower body members 62 and as are providedwith a plurality of perforations tor ports 72 extending through the sidewalls thereof.

A tubular housing member 67 of varying diameter from end to endinterconnects the lower end of the upper body member 62 with the upperend of the lower body member 65' by suitable means such as screws 68. Anintermediate portion 69 of the housing 67 is formed of reduced diameterrelative to the end portions thereof, to fit around the tie rod 63. Ashaped charge unit 73 is positioned in the upper portion of housingmember 67 and is of annular form, with "a central opening through whichtie rod 63 extends. The shaped charge unit 73 comprises an annularshaped ceramic or plastic case 74 which may be formed in two halves tofacilitate assembly. The two portions of the case form aradially-directed, 'annulm cavity having a generally ii-shapedcross-section in which is positioned the shaped charge explosive asshown at 75. An annular metallic liner 7s, V-shaped in crosssection, asviewed in FIG. 1, is provided tor the explosive '75, as is well known inthe shaped charge art. The shaped charge is directed outwardly andslightly downwardly, as shown, and forms, when detonated, acorresponding y directed annular stream or sheet of cutting gases in theform of a downwardly-diverging hollow cone. A similar shaped charge unit77 is positioned within the lower portion of housing member 67 and isdirected outwardly and slightly upward, as shown, to form, whendetonated, a correspondingly directed annular stream or sheet of cuttinggases in the form of an upwardly-diverging hollow cone. The upper andlower cone-shaped streams or sheets of gases thus formed, ifunobstructed, meet or intersect in a. circle or in an annular regionconcentrically surrounding the body of the device, as indicated at F inFIGS. 1 and 2.

Suitable sealing rings 8% and 81 may be provided to form fluid-tightseals between the cases of the shaped charge units and rod 63 and alsobetween the cases and the upper and lower end portion of the housingmember,- 67 to exclude fluid from entering the space forward of theshaped charge cones 76.

Head member 6 is formed with a longitudinal duct 82, and a tube 83extends from the lower end of the duct 82 downwardly into the case 7-4of the upper shaped charge unit 73. The case 74 of the upper shapedcharge also has a longitudinal duct 84 extending therethrough and a tube85 extends from said duct 84 downwardly into thecase of the lower shapedcharge unit 77. Tube 85 makes fluid-tight connection at the upper andlower points where it passes through the wall of the housing member 67,A Primacord or equivalent detonating type of fuse 86 is contained intube 85 and extends through the upper and lower shaped charge units incontact with or closely adjacent to the armular inside surfaces of thebooster charges of the explosive shaped charges 75. An electric blastingcap 87 is secured to the upper end of the Primacord fuse 86, theblasting cap having connected thereto conductors 88 and 89 which areconnected to terminals within the head member, as shown iii-FIG. 1.

As hereinbefore mentioned, shaped charge unit 77 is similar t'o shapedcharge 73 except that the conically shaped gaseous stream therefrom isdirected upwardly and outwardly so as to meet the outwardly anddownwardly diverging, conically shaped gaseous stream of shaped charge73 in a line forming a concentric circle, as indicated at F.

The operation of the invention illustrated is as follows. Upon theapplication of current from the" conductor cable (not shown) toconductor 88, thence through conductor 89 to ground, blasting cap 87 isfired, which detonates fuse 86, which in turn detonates the boostercharges and main explosive charges 75 in shaped charge units 73 and Theresultant gaseous streams from these two shaped charge units, beingconical in shape and directed outward toward a common circle in theformation surrounding the well borehole, cuts out of the formationsurrounding the borehole an annular shaped formation sample C'v'vhich isusually broken into a number of fragments by the reaction of theexplosion, and these fragments are carried by the return rush of wellfluid and gases into the space left between the opposite ends of theupper and lower body members 62 and 65 and from there drop into theinterior of the lower body member 65 and onto the top of the bull plug70,- as best illustrated in FIG. 2. The action of the explosion of theshaped charges is such as to sub stantially disintegrate the shapedcharge units and the central portion of the housing member 67 leavingthe space between the adjacent ends of the body members 62 and 65substantially clear of any obstructions to the passage or the formationsatrlple. fragments into the lower body member 65, as before described.

The sampling apparatus is then hoisted out of the borehole and theformation samples C recovered u While the shaped charges arehereinbefore described as being preferably annular in shape or as havingannular, groove-shaped cavities adapted to produce-convergingly directedsheets of cutting gases,- variations in such shapes may obviously bemade. For example, the shaped charges or cavities, instead of beingtruly annular, may be elliptical, oval, polygonal or the like, inshape,- and produce effective, convergingly-directed sheets of cuttinggases. Therefore the term annular as used hereinbe fore and in theclaims shall be considered to include such other suitable shapes ashereiiibefoie mentioned.

It is to be understood that the foregoing description isillustrativeonly and that the invention is not to be limited thereby,but includes all modifications thereof within the scope of the'inventionas defined in the appended claims.

What is claimed is: a 1. Apparatus-for taking sidewall samples fromfluidfilled well boreholes comprising:

a head member;

a downwardly extending tubular upper body member connected to said headmember;

a downwardly extending tie rod connected at its upper end to said headmember; I g I v a bull plug connected to the lower end of said tie rod;an upwardly extending tubiilaf lower body member connected to said bullplug; 7 I a tubular housing interconnecting the lower end or said upperbody member and the upper end of said lower body member; 7 an uppershaped charge unit within said housing adapted to form when detonated adownwardly dis verging cone of cutting gases penetrative of said housingmember; I

a lower shaped charge unit within said housing adapted to form whendetonated an upwardly diverging cone of cutting gases penetrative ofsaid housing; and means operable from outside said borehole fordetonating said upper and lower shaped charge units simui 2. Apparautsaccording to claim 1 wherein said upper and lower shaped charge unitsare or" annular form.-

3. Apparatus according to claim 1 wherein said lower body member isformed with sidewalls provided with a plurality of ports.

References Cited in the file of this patent UNITED STATES PATENTSSweetman Feb. 26, 1952

1. APPARATUS FOR TAKING SIDEWALL SAMPLES FROM FLUIDFILLED WELL BOREHOLESCOMPRISING: A HEAD MEMBER; A DOWNWARDLY EXTENDING TUBULAR UPPER BODYMEMBER CONNECTED TO SAID HEAD MEMBER; A DOWNWARDLY EXTENDING TIE RODCONNECTED AT ITS UPPER END TO SAID HEAD MEMBER; A BULL PLUG CONNECTED TOTHE LOWER END OF SAID TIE ROD; AN UPWARDLY EXTENDING TUBULAR LOWER BODYMEMBER CONNECTED TO SAID BULL PLUG; A TUBULAR HOUSING INTERCONNECTINGTHE LOWER END OF SAID UPPER BODY MEMBER AND THE UPPER END OF SAID LOWERBODY MEMBER; AN UPPER SHAPED CHARGE UNIT WITHIN SAID HOUSING ADAPTED TOFORM WHEN DETONATED A DOWNWARDLY DIVERGING CONE OF CUTTING GASESPENETRATIVE OF SAID HOUSING MEMBER; A LOWER SHAPED CHARGE UNIT WITHINSAID HOUSING ADAPTED TO FORM WHEN DETONATED AN UPWARDLY DIVERGING CONEOF CUTTING GASES PENETRATIVE OF SAID HOUSING; AND MEANS OPERABLE FROMOUTSIDE SAID BOREHOLE FOR DETONATING SAID UPPER AND LOWER SHAPED CHARGEUNITS SIMULTANEOUSLY.